When operating a turbine and when the heat collection boiler needs to be put out of order for maintenance, it may be necessary to ensure the closure of the bypass section towards the boiler. Similarly, when the gas turbine is reconfigured from a simple cycle to a combined cycle by installing a heat collection boiler, the bypass section towards the exhaust collector must be closed. These sections of the exhaust system may be closed with closure devices such as shutters, doors, guillotine, open or closed ducts, and the like.
The closure devices of these exhaust systems may be subjected to very high constraints due to the temperature differentials that may exist on either side of these devices. Such temperature differentials may create very high mechanical constraints on the closure devices and may create sealing problems during operation. The kinematics of the closure devices must be reliable so as to allow proper operation and good sealing of the mechanisms even after long periods of inactivity.
There are various types of exhaust systems capable of being configured according to an operating mode in a simple cycle or in a combined cycle. In this regard, U.S. Pat. No. 5,299,601 describes a flow bypass system including a panel that may be rotated through a drive mechanism with several articulated branches. Document KR 2011 0104792 describes a similar exhaust system including a flow bypass system with panels connected to a rotary shaft. U.S. Patent Publication No. 2005/268594 describes an electric power plant operating in a combined cycle having a gas turbine associated with a heat collection boiler to collect the exhaust gas of the turbine at high temperature. U.S. Patent Publication No. 2005/005609 describes an exhaust system for a gas turbine that is capable of shifting from a combined cycle to a simple cycle. The exhaust system is fitted with an assembly of ducts that may be maneuvered under the action of a mobile conveyor on a rail.
Nevertheless, it was observed that the various flow bypass solutions provide either an expensive but rapid conversion mechanism or a less expensive conversion mechanism having a longer conversion time. In fact, the most recent mechanisms that are used to maneuver the closure devices of the bypass sections of the exhaust systems may be relatively complex to implement and may require considerable human resources, for example, for the shifting of the various elements.